Information on Service 'AIP DaCHS TAP service'

The AIP DaCHS's TAP end point. The Table Access Protocol (TAP) lets you execute queries against our database tables, inspect various metadata, and upload your own data. It is thus the VO's premier way to access public data holdings. Tables exposed through this endpoint include: dens256, fof, redshifts from the bolshoi schema, columns, services, tables from the glots schema, fof, fofmtree, fofparticles, particles85, redshifts, treesnapnums from the mdr1 schema, rave_dr4 from the ravedr4 schema, alt_identifier, authorities, capability, g_num_stat, interface, intf_param, registries, relationship, res_date, res_detail, res_role, res_schema, res_subject, res_table, resource, stc_spatial, stc_spectral, stc_temporal, subject_uat, table_column, tap_table, validation from the rr schema, columns, groups, key_columns, keys, schemas, tables from the tap_schema schema.

For a list of all services and tables belonging to this service's resource, see Information on resource '__system__/tap'

Service Documentation

This service speaks TAP, a protocol designed to allow the exchange of queries and data between clients (that's normally something running on your computer) and servers (e.g., us).

You will want to use some sort of client to query TAP services; examples for those include:

You can, in a pinch, use our service in an XML-enabled browser, too. Under Overview, look for the bullet point on tap and follow the link to "this service". Then, click on "New job..." in the job list, enter your query, click "Set query", then "Execute query". Reload the page you are redirected to now and then to see when your job is finished, then retrieve the result.

The queries this service executes are written an a dialect of SQL called ADQL. You need to learn it to use this service. See our ADQL tutorial. Also do not miss the local examples.

By the way, for quick ad-hoc queries from within a browser, our ADQL form service may be more convenient than TAP.

Also see the table metadata of the tables exposed here.

Local information: This service may put a much lower limit on uploads in sync queries than advertised in the table metadata. Unfortunately, current TOPCAT versions don't give terribly helpful error messages when the server rejects a query because the attached upload is too large (something like “Error writing request body to server“). If that happens to you, just switch to asynchronous querying (in TOPCAT, that's in the “Mode” combo box just above the query editor).

Issues

For information on our ADQL implementation, see the ADQL service info.

If multiple output columns in a query would end up having the same name, in the output VOTable they are disambiguated by appending underscores. This is in violation of the specification, but since fixing it would require rather intrusive changes into our software and it is not clear why one should want to use names when they are not unique to begin with, this will probably not be fixed.

Overview

You can access this service using:

This service is published as follows:

local means it is listed on our front page, ivo_managed means it has a record in the VO registry.

Input Fields

The following fields are available to provide input to the service (with some renderers, some of these fields may be unavailable):

NameTable Head DescriptionUnitUCD
format Format Deprecated alias of RESPONSEFORMAT N/A N/A
lang Lang A name of a language that QUERY should be parsed as. See capabilities for what you can pass in here. N/A N/A
maxrec Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
maxrec Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
query Query The query to be executed. N/A N/A
request Request Type of operation requested; this can be doQuery or getCapabilities. Preferably, don't pass it at all. N/A N/A
responseformat Output Format File format requested for output. N/A meta.code.mime
responseformat Output Format File format requested for output. N/A meta.code.mime
upload Upload A TAP-compliant upload; roughly: (tablename,source-uri), where source-uri can also have a param: scheme. N/A N/A
verb Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A
verb Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A
version Version Don't use this parameter. You'll only break stuff. N/A N/A

VOResource XML (that's something exclusively for VO nerds)